Should I change my uni joints?

[crackers]

My Moggy was suffering from extremely loud noises when driving associated with vibration. One suggestion was a seized uni joint. A head under the car showed that the old girl had grease nipples on the joints (OMG, someone fitted the correct bits ) and over the length of a good drive, the vibration and noise reduced. Ah ha, I thought, it WAS the uni joints, and seeing I had to buy some brake bits anyway, I ordered new joints at the same time.

I got the bits and fixed the front brakes. During the test drive for that, I noticed that the noise and vibration was much better... but I didn't take too much notice because I was worrying about brakes.

Yesterday, I pulled the tailshaft, and found that the uni joints at both ends were both smooth and free.

So, bearing in mind that I already have new uni joints sitting on my bench next to the tailshaft, should I just give the old joints another shot of grease and put it all back in the car or should I change the uni joints? I've heard that changing them can be troublesome and have read other stories of new joints throwing the whole thing out of balance.

[philthehill]

Whilst they may be free and smooth is there any rotational play in the joints?
Try turning the rear flange and propshaft against other i.e. backwards/forwards and the same at the front.
If no play I would advise leaving well alone.
If the propshaft is removed mark the diff flange and the propshaft rear flange against one another, do the same for the joints, putting it all back together in the same orientation should alleviate any out of balance problems.
Keep the new joints as you may need them at a later date.
Check the propshaft tube for any large lumps of crud i.e. underseal as that could cause the propshaft to go out of balance and cause a vibration.
With the better seals fitted these days there is no requirement for grease seals as they are packed for life at the factory.
Having a grease nipple fitted is not all good as furious greasing can displace the bearing joint seals which will allow water and crud into the bearing so causing rapid wear. Grease nice and steady and only a couple of pumps of the grease gun are required.
Phil

[crackers]

Whilst they may be free and smooth is there any rotational play in the joints?
Try turning the rear flange and propshaft against other i.e. backwards/forwards and the same at the front.
If no play I would advise leaving well alone.

Yeah, I did that and there was no rotational play. Everything seemed as it should be. The only that that wasn't was when I pumped in new grease (probably overly enthusiastically from your description), some seals produced some black 'goop' (wasn't nice enough to call grease) before fresh while others produced nothing before fresh.

I refitted the tailshaft and went for a long drive. Still very very noisy. A lot of that (maybe all of it now) is exhaust - the muffler is shot but rather than just getting a sporty sounding exhaust, I seem to be getting a lot of booming through the car. Before greasing the unis, there was another, very loud noise laid over the top of this - that's now gone... I think.

[bmcecosse]

I would leave well alone meantime and fix the exhaust first...

[crackers]

I would leave well alone meantime and fix the exhaust first...

Sound advice. Thanks.

Please ignore the dreadful pun.